It's not often you can actually say "case closed", but in this case it's literally true: climatologist Michael Mann has been cleared of all wrongdoing by the Inspector General of the National Science Foundation.
Did I say "has been cleared"? I meant has been cleared once again, since there have been several investigations into his research and Dr. Mann has been cleared of all charges every single time (like here and here). All of this stemmed from the "ClimateGate" nonsense of the past couple of years, where leaked emails were taken hugely out of context by the press and climate change deniers, and used to smear scientists. Dr. Mann was at the center of the whole manufactured controversy, being the biggest target of the people who want to deny the Earth is warming up.
This latest, and hopefully last, investigation into Dr. Mann's research (PDF) again shows he is not guilty of misconduct. A couple of the report conclusions are worth pointing out:
We found no basis to conclude that the [Climategate] emails were evidence of research misconduct or that they pointed to such evidence.
That's clear enough, I think. They also said:
There is no specific evidence that [Mann] falsified or fabricated any data and no evidence that his actions amounted to research misconduct.
A big claim by the deniers is that researchers were using "tricks" to falsify conclusions about global warming, but the NSF report is pretty clear that's not true. The most damning thing the investigators could muster was that there was "some concern" over the statistical methods used, but that's not scandalous at all; there's always some argument in science over methodology. The vague language of the report there indicates to me this isn't a big deal, or else they would've been specific. The big point is that the data were not faked.
What does this mean for global warming? A lot of these attacks can be traced back to the famous "hockey stick" diagram, showing how Earth's temperatures have been increasing rapidly in recent times. This graph is what really clinches the idea of man-made global warming, and so has been the epicenter of the manufactroversy. The fact that Dr. Mann has been cleared again, and that his data are good, shows that this graph is even more solid -- or at least is not as weak as so many would lead you to believe.
And what does this mean about "ClimateGate"? That's clear enough: all the outrage, all the claims of fraud and fakery, were just -- haha -- hot air.
Not that this will stop or even slow down the denial machine. Politicians from the Virginia State Attorney General to members of the House of Representatives have been on what I would characterize as witch hunts. Dr. Mann has been vocal in his opposition, and I applaud him. Still, needless to say, the attacks will continue.
Here are the facts: the Earth is warming up. The rate of warming has increased in the past century or so. This corresponds to the time of the Industrial Revolution, when we started dumping greenhouse gases into the atmosphere. Greenhouse gases warm the planet (hence the name) -- if they didn't we'd have an average temperature below the freezing point of water. Carbon dioxide is a greenhouse gas which is dumped into the atmosphere by humans to the tune of 30 billion tons per year, 100 times the amount from volcanoes. And finally, approximately 97% of climatologists who actually study climate agree that global warming is real, and caused by humans.
Those are simply the facts. It's not hard to connect them, as long as you stick to reality and don't let ideology sway you.
Tip o' the thermometer to DeSmogBlog.